merge: origin/main v1.1.0.0 into garrytan/fix-checkpoints

Main shipped browse Puppeteer parity (v1.1.0.0 — goto file://,
load-html, screenshot --selector, viewport --scale). Resolved conflicts:

- VERSION / package.json: bumped 1.0.1.0 → 1.1.1.0 (main is 1.1.0.0,
  this branch lands next).
- CHANGELOG: moved the /context-save + /context-restore entry to the
  top as v1.1.1.0, above main's v1.1.0.0.
- Migration: renamed gstack-upgrade/migrations/v1.0.1.0.sh →
  v1.1.1.0.sh (matches new version). Test path updated. Migration
  version string inside the script also updated.

No overlap between browse changes and context-save/context-restore code.
SKILL.md files regenerated via bun run gen:skill-docs --host all per
CLAUDE.md's "never resolve generated files by accepting either side"
rule. Golden fixtures (claude/codex/factory ship) regenerated.

bun test: 0 failures. Migration ownership guard: 7/7 pass (~85ms).

test/migration-checkpoint-ownership.test.ts

@@ -5,7 +5,7 @@ import * as path from 'path';
 import * as os from 'os';
 
 const ROOT = path.resolve(import.meta.dir, '..');
-const MIGRATION = path.join(ROOT, 'gstack-upgrade', 'migrations', 'v1.0.1.0.sh');
+const MIGRATION = path.join(ROOT, 'gstack-upgrade', 'migrations', 'v1.1.1.0.sh');
 
 function runMigration(tmpHome: string): { exitCode: number; stdout: string; stderr: string } {
   const result = spawnSync('bash', [MIGRATION], {
@@ -28,7 +28,7 @@ function setupFakeGstackRoot(tmpHome: string): string {
   return gstackDir;
 }
 
-describe('migration v1.0.1.0 — checkpoint ownership guard', () => {
+describe('migration v1.1.1.0 — checkpoint ownership guard', () => {
   let tmpHome: string;
 
   beforeEach(() => {